Distinguishing Characteristics

Adult Black-capped Chickadee, Ithaca, NY, 13 February.

Black-capped Chickadee head detail, Edmonton, AB, 24 December.

Adult Black-capped Chickadee, Pacific NW subspecies, Ridgefield NWR, WA, 19 February.

Adult Black-capped Chickadee, wing detail, Ithaca, NY, 29 January.

Description

To the human eye, sexes generally alike in plumage (but see below), with males slightly longer than females in wing and tail, and slightly heavier in body mass (Desrocher 1990). Juveniles essentially the same as adults in overall plumage pattern, but plumage is somewhat looser in texture. Solid black cap and bib, white cheeks, unstreaked greenish gray back, buffy flanks and crissum, dark grayish wings and tail. Bill black; legs and toes bluish gray, iris dark brown. Wings rounded with 10 primaries. Tail long. Within sexes, adult wings longer than those of younger birds (and average lengths vary with subspecies). Length 12.3–14.6 cm; mass 10–14 g.

Spectrophotometry reveals subtle sex differences in plumage color, where males have brighter white feathers and deeper black feathers than females (Mennill et al. 2003a). The area of the black bib is also larger in males (Mennill et al. 2003a).

Identification

Very similar to its southern relative the Carolina Chickadee (Poecile carolinensis), and in the few places where their ranges overlap, the two occasionally hybridize (see eBird for range discussion). The two are best distinguished by voice, with Black-capped Chickadee having a slower, hoarser call. Their songs also differ, with Black-capped having a simpler two-part song, versus the more drawn out three-noted song of Carolina. Plumage differences are subtle, but Black-capped has pale edgings on the wing coverts (especially on greater coverts) and secondaries that are broader and more conspicuous than those of typical Carolina Chickadee. Black-capped generally has a messier border where the dark bib meets the upper breast, whereas Carolina is neater in this regard. Carolina Chickadee tail/wing ratio < 0.9; Black-capped Chickadee tail/wing ratio > 0.9 (Pyle et al. 1997). Mountain Chickadee (Poecile gambeli) somewhat similar to Black-capped, but is slightly longer-billed and longer-winged, with noticeable white supercilium (stripe above eye) and plainer grayish wings. Beware of worn summer Mountain Chickadees that lack obvious supercilium.